4.3 The Onega Basin

Melezhik, Victor A.; Медведев, П. В.; Светов, С. А.

doi:10.1007/978-3-642-29682-6_9

Cited by 13 publications

(31 citation statements)

References 21 publications

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“…5) as well as lateral variations (Melezhik et al, 2012b). In the south-western part of the Onega palaeobasin, the TF succession starts with a c.…”

Section: Depositional Age and Lithostratigraphymentioning

confidence: 97%

“…The bulk lithology of the TF as documented in Core 11A is as diverse as in many other studied sections (e.g., Melezhik et al, 2012b). Carbonate rocks are the dominant lithology and include massive, bedded, crystalline and stromatolitic dolostones, dolarenites, dolorudites, dolomarls, in situ and redeposited dissolution breccias.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…This was the time when the volcano-sedimentary succession of the ZF was deposited, followed by voluminous subaqueous mafic magmatism. This was accompanied by an unprecedented accumulation of C org -rich rocks and formation of the earliest known petrified giant oilfield (Melezhik et al, 2009;Melezhik et al, 2012b) representing the worldwide SHE (e.g., Melezhik et al, 2005a).…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…1) (Fig. 3), which is radiometrically poorly constrained (reviewed in Glushanin et al, 2011;Melezhik et al, 2012b). Basin filling was interrupted by numerous non-depositional breaks and several episodes of erosion of unknown duration.…”

Section: Introductionmentioning

confidence: 96%

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Carbonate deposition in the Palaeoproterozoic Onega basin from Fennoscandia: a spotlight on the transition from the Lomagundi-Jatuli to Shunga events

Melezhik

Fallick

Brasier

et al. 2015

Earth-Science Reviews

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Several deep drillholes were made in the Onega palaeobasin by the Fennoscandian Arctic Russia-Drilling Early Earth Project (FAR-DEEP) of the International Continental ScientificDrilling Program (ICDP). These provided fresh core material documenting the LomagundiJatuli Isotopic Event (LJIE), its termination, and the start of the Shunga Event (SHE) of an enhanced accumulation of organic matter. The cored section represents the most complete known record of the end of the LJIE.The late phase of the LJIE, recorded in FAR-DEEP Core 11A, is represented by the upper part of the Tulomozero Formation (TF), a 300-m-thick unit composed of variegated dolostones, siltstones and shales. Accumulated under oxic conditions on a shallow-water carbonate platform, the TF hosts the earliest known thick formations of halite and massive anhydrite. Low-temperature greenschist facies metamorphism caused partial recrystallisation of the rocks; however, a primary carbonate phase, the dolomite, exhibits a negligible degree of post-depositional alteration of the carbon isotope system. The dataset of 46 bulk-carbonate analyses of carbon and oxygen isotopes yielded  13 C carb ranging between +6.8 and +11.8‰, and revealed a positive excursion from +8 to +11.8‰ followed by a decline to +8‰ towards the top of the 300-m-thick succession.The cored part of the overlying Zaonega Formation (ZF) recovered in holes 12AB and 13A is an 800-m-thick unit composed of mixed siliciclastic-carbonate facies with numerous mafic lava flows and tuff beds intruded by gabbro sills. The formation represents an unprecedented episode of enhanced accumulation of organic-rich rocks and preserves the earliest known supergiant, petrified oilfield, all typifying the SHE. The sedimentological, petrographic, geochemical and C-and O-isotopic study of over 800 m of core throughout the ZF suggests that the initial carbonate deposition occurred in a lacustrine environment, then rapidly proceeding through a lagoonal setting to a rifted deepwater shelf, and finally to a carbonate platform. Both the deepwater shelf and the platformal settings are marked by organic-rich environments. The primary dolomite was potentially exposed to syn-and post-depositional hydrothermal/metasomatic alterations, organic matter diagenesis, metamorphic mineral reactions, CO 2 degassing, and finally a low-temperature, post-metamorphic calcitisation resulting in overall large fluctuations of  13 C carb between -22 and +8‰. The dataset of over 413 bulk-carbonate analyses of carbon and oxygen isotopes, screened petrographically and A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT4 geochemically against post-depositional alteration, revealed 28 least-altered samples within three stratigraphic intervals, suggesting multiple positive and negative  13 C carb excursions throughout over 1000 m of stratigraphy. A shift from +5 to +9‰ followed by a drop to near zero values marks the lower part of the ZF. A  13 C carb decline from +8‰ to below zero in the middle and upper part of the ZF defines the end of t...

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“…5) as well as lateral variations (Melezhik et al, 2012b). In the south-western part of the Onega palaeobasin, the TF succession starts with a c.…”

Section: Depositional Age and Lithostratigraphymentioning

confidence: 97%

Section: Accepted Manuscriptmentioning

confidence: 99%

Section: Accepted Manuscriptmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

See 2 more Smart Citations

Carbonate deposition in the Palaeoproterozoic Onega basin from Fennoscandia: a spotlight on the transition from the Lomagundi-Jatuli to Shunga events

Melezhik

Fallick

Brasier

et al. 2015

Earth-Science Reviews

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“…Онежская структура -это сложно пос-троенный палеопротерозойский прогиб, вме-щающий и современную впадину Онежского озера, выполненный вулканогенно-осадочными отложениями палеопротерозоя. Стратиграфия, геолого-геофизическое строение, палеогео-графия и тектоника ОС отражены в ряде обоб-щающих работ [Глубинное строение…, 2004;Светов, Свириденко, 2005;Минц и др., 2010;Онежская…, 2011;Melezhik et al, 2013;и др. ].…”

Section: Introductionunclassified

On Recent Faults and Paleoseismic Fractures in the Palaeoproterozoic Onega Structure of the Baltic Shield

Никонов¹,

Zykov²,

Nikonov³

et al. 2017

Proceedings of KarRC of RAS

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В пределах Онежской структуры Фенноскандинавского (Балтийского) щита Восточно-Европейской платформы обнаружены специфические морфоструктуры, отражающие импульсные сейсмотектонические события. Анализ литературных данных показал, что подобные морфоструктуры выделялись российскими учеными в этих местах уже с XIX века. Изучение их эволюции, кинематики и соотношение морфоструктур с палеопротерозойской геологической структурой региона выяви-ли ряд признаков аккомодации новейших тектонических движений к древней струк-туре. В частности, установлена приуроченность к ней поздне-и послеледниковых разрывов. Обосновывается отнесение большинства из выявленных морфоструктур к дислокациям, сформированным за счет мощных сейсмических воздействий на ряде участков. Подтверждается длительность эволюции палеопротерозойских ин-траконтинентальных морфоструктур и расширяется возможность уточнения оце-нок долговременной сейсмической опасности в области тектонической аккомода-ции Фенноскандинавского щита в пределах флексуры А. А. Полканова. К л ю ч е в ы е с л о в а: Восточно-Европейская платформа; Фенноскандинавский щит; Онежская структура; палеоземлетрясения; тектоническая аккомодация; не-отектоника; палеосейсмодислокации. A. A. Nikonov, A. V. Poleshchuk, D. S. Zykov. ON RECENT FAULTS AND PALEOSEISMIC FRACTURES IN THE PALAEOPROTEROZOIC ONEGA STRUCTURE OF THE FENNOSCANDIAN SHIELDSpecific morphological structures corresponding to impulsive seismotectonic events were identified within the Onega structure of the Fennoscandian (Baltic) shield of the East European platform. Analysis of data from the literature showed that similar morphological structures have been detected by Russian scientists in this area already since the 19 th century. The study of evolution, kinematics, and the correlation of the morphostructures with the region's Palaeoproterozoic geological structure suggest that recent tectonic movements have been accommodated to the ancient structure. In particular, late-and postglacial faults were found to be associated to this structure. We prove that a majority of the identified morphostructures are dislocations caused by strong seismic impacts in a number of areas. The prolonged evolution of the Palaeoproterozoic intracontinental morphostructures is confirmed, and the possibilities for refining the estimates of longterm seismic hazard in the area of tectonic accommodation of the Fennoscandian shield in the central sector of the Polkanov flexure are expanded.

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Hydrothermal Tourmaline from the Girvas Paleovolcano (Onega basin, Karelian Craton): Morphology and Chemical Composition

Svetova

Светов

2023

Springer Proceedings in Earth and Environmental Sciences

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4.3 The Onega Basin

Cited by 13 publications

References 21 publications

Carbonate deposition in the Palaeoproterozoic Onega basin from Fennoscandia: a spotlight on the transition from the Lomagundi-Jatuli to Shunga events

Carbonate deposition in the Palaeoproterozoic Onega basin from Fennoscandia: a spotlight on the transition from the Lomagundi-Jatuli to Shunga events

On Recent Faults and Paleoseismic Fractures in the Palaeoproterozoic Onega Structure of the Baltic Shield

Hydrothermal Tourmaline from the Girvas Paleovolcano (Onega basin, Karelian Craton): Morphology and Chemical Composition

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